Metering fuel pump



Oct., 3, 1939. H. v. HONN METERING FUEL PUMP Original Filed Sept. 26, 1934 INVENTOR.r

HARLAN VERNE HON/V.

BY hll Y 'u' j 1 A TTORN YS.

Patented Oct. 3, 1939 UNITED STATES METERING FUEL PUMP Harlan Verne Honn, San Francisco, Calif.

Original application September 26, 1934, Serial Divided and this` application August 9, 1937, Serial No. 158,131

2 Claims.

My invention relates to metering fuel pumps, and more particularly to a metering pump which may be utilized to supply liquid fuel to a heavy oil engine. 'I'his application is a division of my v prior application, Serial No. 745,573, filed September 26, 1934, entitled Internal combustion engine, now Patent No. 2,091,987, Adated September 7, 1937.

Among the objects of my invention are: To provide a means of controlling the speed of a heavy oil engine; to provide accurate means for metering fuel charges for a heavy fuel engine; to provide variable means for metering fuel charges for heavy oil engines; and to provide a simple and efficient variable delivery metering pump.

Other objects of my invention will be apparent or will be specifically pointed out in the description forming a part of this specification, but I do not limit myself to the embodiment of the invention herein described, as 'various forms may be adopted within the scope of the claims.

Referring to the drawing:

Fig. 1 is a diagram reduced to lowest terms, showing the interrelation of parts in a single cylinder heavy oil engine.

Fig. 2 is a longitudinal sectional View of a preferred type of fuel metering pump.

Figs. 1- and 2 are duplicates of Figs. 2 and 3 of the parent application referred to above.

My invention may be more fully understood by direct reference to the drawing.

In Fig. 1 I have shown a preferred type of heavy oil engine such as was described and claimed in my cited application supra, but it is to be distinctly understood that the metering pump forming the subject matter of the present application is adapted to be used with any type of machine where a variable and predetermined charge of liquid is desirable.

In this preferred form of engine, a crank shaft I is provided with the crank throw 2 to which a connecting rod 3 is attached at one end, the other end being attached to a piston 4 reciprocating in the usual cylinder 5. 'Ihe piston, as is customary, is provided with rings 6. A crank shaft gear 'l drives an inlet cam shaft gear 9 having a valve cam I0 mounted thereon, the latter operating a push rod II, and through the medium of a bell crank I2, operates an intake valve I4 opening into a cylinder head chamber I5 and controlling a source of air I6. An exhaust gear I1 is also driven by the crank shaft gear, the exhaust gear driving an accessory shaft I9 (Cl. 'M -568) against a push rod 2I operating an exhaust valve 22 through the exhaust bell crank 24.

The fuel charge is supplied to the engine in ignited condition through an injection port 25 from an auxiliary combustion cylinder 25 having an igniter piston 21 reciprocated therein through the medium of an igniter piston rod 29 bearing against an igniter cam 30 on the auxiliary shaft I9. The fuel charge is ignited by compression created by the piston in the auxiliary chamber. A surge valvel SI is positioned in the top of the auxiliary cylinder 26, and the igniter port 25 is continued past the top of this valve as an air passage 32. The surge valve traps the ignited charge until a predetermined pressure is reached and then discharges into the main cylinder. A fuel valve 34 closes air passage 32 from an inlet port 35, and the Valve is maintained in place by a fuel valve spring 36. An annular fuel channel 37 is covered by fuel Valve 34 under normal conditions, and the outlet fuel channel 37 is supplied from a fuel pipe 38 through a check valve 40. When inlet port 35 is uncovered, fuel is swept into the auxiliary cylinder from fuel channel 37. The fuel is supplied to the fuel pipe 38 from a metering pump shown diagrammatically in Fig. 1, which will now be described in detail, as shown iny Fig. 2.

A pump frame cylinder 4I is fitted at one end with a pump block 42 held in place .by .a lock nut 44. A single inserted pump sleeve 45 passes through the block, if for use with a single cylinder engine, or a plurality of sleeves may be used if several cylinders are supplied.

A tubular fuel piston 46 slides in the sleeve 45, and is extended by a fuel piston spring 41 bearing against the lower end of the tube and against a check valve fitting 48 screwed in the top of the block. This check valve fitting is supplied with the usual outlet port 49 connecting to fuel pipe 38, ball valve 5I! and ball spring 5I. The lower end of the tubular piston is provided with a ball bearing 52 rolling on the face of a rotating plate 54 which is provided with a peripheral cam 55 positioned and adapted to raise the piston 46 when rotated.

The rotating plate 54 has an extended stem 56 which, by means of an internal spline 51, slides freely on a fuel pump drive shaft 59. The rotating plate and extended stem are set in a screw threaded bearing 60 which is raised or lowered by rotating a bearing drive sleeve 6I by means of a rack 62 and pinion 64. 'Ihrust is taken up by an apertured thrust plate 65 fastened to the pump frame cylinder 4I and bearing on the top of the drive sleeve 6I. Rotation or angular movement of the threaded bearing 60 is precluded by providing a groove 12 therein transversely of the threads, and extending into such groove an extension 13 formed integrally with the thrust plate '65. A collar i5 surrounding the extended stem 56 and pinned thereto, serves to maintain the threaded bearing 60 against longitudinal displacement with respect to the stem '5.

Fuel, of the relatively heavy oil type, if the device is used with a Diesel type engine, may be supplied to the fuel pump chamber l0 under slight pressure from any convenient storage device as by pump 1I. A fuel pump inlet 12 is provided slightly below the top of the pump chamber, and is not provided with any check valve.

At some time after the firing stroke of the engine, the time being at any portion of the complete cycle when the fuel valve 3d is closed and therefore not critical, a meteredcharge of fuel is deposited in annular fuel chamber 31. The metering is accomplished by regulating the `distance the tubular fuel piston 45 travels past the fuel pump inlet l2. This regulation is accomplished by raising cr lowering the rotating plate 54, and the raising mechanism may be said to constitute the throttle of the engine.

As there is no check valve in the fuel pump inlet, and as I adjust the pressure in the fuel supply pipe to be less than the pressure oifered by the ball valve 50, all oil or fuel in the fuel pump chamber on the upstroke of the fuel pump piston will pass back into the fuel supply line up to the time that the piston covers the fuel pump inlet l2, but after the piston crosses the inlet the additional travel of the piston forces oil through the fuel pipe 38 into the annular fuel chamber 3l, the amount depending on the extent of travel of the piston edge past the fuel pump inlet. The charge of liquid fuel in the annular chamber may thus be accurately regulated and metered, the ball valve 50 keeping it there until used by the engine. .The cycle is then repeated.

I have thus provided and shown an application of a metering pump that can be accurately controlled and regulated as to output while running.

I claim:

1. Cam and adjusting means for cyclically reciprocating a pump piston comprising a support, a shaft rotatably journaled in said support, a hub having a pump piston positioning plate formed integral therewith and slidable but nonrotatably disposed on said shaft normal thereto, a cam extending from said plate so positioned and arranged as to enable contacting such a piston once during each revolution of said shaft whereby such piston may be reciprocated, and means for axially adjusting said cam and plate comprising an externally threaded sleeve having a sliding fit about said hub adjacent said plate, a collar pinned to said shaft adjacent said sleeve arranged to prevent longitudinal movement of said threaded sleeve along said hub, an internally threaded sleeve positioned around and engaged threadably with said externally threaded sleeve, means for preventing longitudinal movement of said internally threaded sleeve, means for preventing rotation of said externally threaded sleeve, a gear fixed to and mounted concentric with said internally threaded sleeve, a rack journaled in said support in engagement with said gear, said rack being capable of longitudinal movement.

2. Cam and adjusting means for cyclically reciprocating a pump piston comprising a support, a shaft rotatably journaled in said support, a hub having a pump piston positioning plate formed integral therewith and slidable but nonrotatably disposed on said shaft normal thereto, a cam extending from said plate so positioned and arranged as to enable contacting such a piston once during each revolution of said shaft whereby suoli piston may be reciprocated, an externally threaded sleeve rotatably mounted about said hub, means for preventing rotation of said sleeve, means for preventing longitudinal movement thereof relative to said plate, an interiorly threaded sleeve engaged with and about said exteriorly threaded sleeve, said support forming a sliding fit about said interiorly threaded sleeve, means for preventing longitudinal movement of said interiorly threaded sleeve, a gear fixed to and concentric with said internally threaded sleeve, a rack journaled in said support and engaging said gear, said rack being capable of longitudinal movement.

HARLAN VERNE HONN. 

